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MisterP

join:2012-10-11
US

1 edit

[Speed] Ordered Blast tier (25/4) but am getting 16/2-Mid TN


During PowerBoost

After PowerBoost
Hello all,

First of all, apologies for the attachments; not sure how to put them in the body of the post where I can explain them in sequence.

I am in Nashville, TN and I recently had Comcast HSI installed and got the Blast tier which I was told by a corporate Xfinity rep at a Best Buy was 25Mbps Down and 4Mpbs up WITHOUT PowerBoost here in the Nashville market (And 30 Down WITH powerBoost; Upload was not guaranteed). Well, the installation tech came, ran the cable he needed to run to the room I wanted internet in, removed unneeded lines, terminated the unneeded ports on the splitter, and ran all signal and line tests. Everything was within range and checked out so, finally, he tested my speed via IE9 on my Win7 laptop (Which has no firewall and MSE running for AV) plugged directly via Cat 5e into my Motorola Surfboard SB6121 (I have no other networking equipment connected). Speed and Ping results were identical to these below:

SpeedTest:


PingTest:


I thought it was curious that the PowerBoost had not kicked in during our tests but he said that happens quite a bit. At any rate, I was very satisfied and all was well so I thought that was that. Later, I remembered reading on this forum, that people were testing the true throughput of their connections irrespective of PowerBoost by downloading large files and monitoring bandwidth in real time using a meter and I wanted that extra peace of mind so I decided to do it as well. I installed BitMeter 2 and set its gauge to 'Mbps' and proceeded to download several large files (Service Pack 3 for XP, a TekZilla Podcast, and other large test files).

What I found was that the 25 Down seems to be the PowerBoost speed and my TRUE speed is ~16Mpbs. I have screengrabbed one of the files being downloaded during and after PowerBoost to illustrate this point (They are the two attached images at the head of the post). During the PowerBoost, you can see it is ~25Mbps; after the PowerBoost it is ~16 Mbps. I have confirmed this drop and this consistent post PowerBoost speed of 16 down on every file I have tested the connection with.

To further verify the problem, I used the DiffProbe Shaper Module (I don't suspect my traffic is being shaped, I used this tool as it does long term upload and downloads so you get a post-PowerBoost reading). It also confirmed what I was seeing. PowerBoost speeds of 25 Down/4 Up and after PowerBoost speeds of 16/2. Below are my results:

Estimating capacity:
Upstream: 4234 Kbps.
Downstream: 25558 Kbps.
 
The measurement will take upto 2.5 minutes. Please wait.
 
Checking for traffic shapers:
 
Upstream: Burst size: 4308-4379 KB;
Shaping rate: 2090 Kbps.
 
Downstream: Burst size: 9517-10036 KB;
Shaping rate: 15978 Kbps.
 

I ran the DiffProbe 4 times total and each time got near identical results as above. Capacity is 25/4 but actual stream rates were 16/2.

I called Comcast and the agent I spoke with confirmed with Billing that I was indeed on the Blast plan but that I should be getting 20 down after PowerBoost, not 25 down but that my upload of 4 was correct. I have heard even more different rates from a local Comcast office I spoke with as well but the corporate Xfinity rep assured me that 25/4 is the new Blast tier for this market.

Anyways, after the agent confirmed my billing status, he reset the modem, and ran some tests on my line and asked me to test another download. I re-downloaded a file and got the same results as before. He said he would send out a service tech on an escalated ticket to get it resolved as he believes it is a line issue. I'm not so sure it is a physical infrastructure issue as the 16/2 speeds I'm getting are very consistent and without much fluctuation as would usually be the case if the lines had interference, out of range dB levels or other issues.

Extra data that may be requested is below:

Modem I am using-
Model Name: SB6121
Vendor Name: Motorola
Firmware Name: SB_KOMODO-1.0.6.6-SCM00-NOSH
Boot Version: PSPU-Boot(25CLK) 1.0.12.
Hardware Version: 5.0
Serial Number: xxxx
Firmware Build Time: Apr 17 2012 15:09:37

Sorry for the long post but I felt it necessary to give as much information as possible so that someone might be able to help. If you need any more info, let me know. Thanks in advance for your replies.

ExoticFish

join:2008-08-31
Stuarts Draft, VA

Re: [Speed] Ordered Blast tier (25/4) but am getting 16/2

Well, as you can see you're on 16/2 sustained with about 25/4 with PowerBoost. It could be that your specific area hasn't been upgraded to the new plans yet but 16/2 is indeed Blast.
--
»www.VAJeeps.com


MisterP

join:2012-10-11
US

That's what I originally thought as when I was doing my initial info gathering on what ISP to get, Blast popped up as 16/2 but a corporate Xfinity rep, installation tech and phone support agent have all told me it should be either 20 or 25Mbps Down depending on who you talked to and 4 Mbps up without PowerBoost interfering.

In fact, the corporate rep said that Blast hadn't been 16/2 for over two years in Nashville/Middle TN and that they we prepping for making Blast the 50 down tier and Extreme 50 to become 105 so they could make way for the Extreme 300 that is coming within a year or so. Not sure if there are other Nashville/Middle Tennessee people around that can confirm the Blast speeds I should be getting but that would help.



EG
The wings of love
Premium
join:2006-11-18
Union, NJ
kudos:9

1 recommendation

FWIW, It could be that 15-16/2 is now called the Performance Plus tier in you area. Heaven help if Comcast is ever straightforward with their naming conventions....


medbuyer

join:2003-11-20
kudos:4
reply to MisterP

ask NetFixer See Profile he's around that area and he's knowledgeable on the subject matter....though he's a biz account customer like me...


thatguyzp

join:2005-02-22
Smyrna, TN
reply to MisterP

Sounds like they pushed an incorrect config to your modem or something.

quote:
Estimating capacity:
Upstream: 6357 Kbps.
Downstream: 36221 Kbps.

The measurement will take upto 2.5 minutes. Please wait.

Checking for traffic shapers:

Upstream: Burst size: 9646-9720 KB;
Shaping rate: 4293 Kbps.

Downstream: Burst size: 19250-19731 KB;
Shaping rate: 26618 Kbps.

There's my ShaperProbe results for Blast down in Smyrna.

I'd try the Comcast Direct forum here, they should be able to sort it out for you.

MisterP

join:2012-10-11
US

Thanks so much for confirming thatguyzp. I asked about the config file, profile or software they may have pushed to the modem when I was on with the agent but he told me whatever you are set to in the billing system is what the system automatically pushes to you so there's no error in that he says

But the profile does sound more like the culprit as it falls in line with what I was seeing in my tests and what I tried to explain to them.

One thing I did just remember about the install; He said he used the RG-59 cable that was already in place and since he didn't have enough length to move it to the room I was in, he spliced it with RG-6 and put a barrel joint on it. That could be what the agent on the phone was talking about with line issues maybe? But the tech said he tested it and it was ok to do. Maybe having the tech that is coming out on the escalated ticket run a new homerun of RG-6 straight to my modem would help? I don't know how much difference it would make on the speed though; the profile is still probably the main issue.


ExoticFish

join:2008-08-31
Stuarts Draft, VA

Post your signal levels.
--
»www.VAJeeps.com


MisterP

join:2012-10-11
US

Click for full size
Signal Levels
Edit: Is it normal to have only three upstream channels?

ExoticFish

join:2008-08-31
Stuarts Draft, VA

Signals are fine. Yes 3 upstream is possible. So you can exclude that cable as the cause.
--
»www.VAJeeps.com



NetFixer
Snarl For The Camera Please
Premium
join:2004-06-24
The Boro
Reviews:
·Cingular Wireless
·Comcast Business..
·Vonage
·Comcast
reply to MisterP

said by MisterP:

Edit: Is it normal to have only three upstream channels?

It appears to be normal in the Nashville area (some areas only bond two upstream channels, and some areas still don't have upstream bonding at all).

I have 4x3 bonding with my SB6121, and I also had it with my SMCD3G-CCR.
--
We can never have enough of nature.
We need to witness our own limits transgressed, and some life pasturing freely where we never wander.

MisterP

join:2012-10-11
US

This is the resolution for anyone who sees this in the future:

It turned out that Comcast pushed the wrong profile to my modem (The Performance tier instead of the Blast) because they don't have access to the corporate Xfinity 'Vision' billing system so they didn't see the hit code for Blast. Had to call the corporate rep and he sent a signal to my modem for Blast. And the tech ran a homerun to my modem of pure RG-6 just to take the old RG-59 out of the equation.

One thing I did notice that was strange was that after my modem got the Blast profile downloaded to it, my connection worked and my new speed was confirmed but when I logged into the modem (192.168.100.1) I noticed that on the status page it said Offline for the modem status, on the signals page one of the upstream channels said T4 Timeout and my Logs had almost a dozen new errors that said Critical and warning next to them.

Can anyone tell me what that may be about? I've heard other posts on here of others with SB6121s getting lots of errors but I didn't start seeing them until I got upgraded to Blast.



telcodad

join:2011-09-16
Lincroft, NJ
kudos:5

said by MisterP:

One thing I did notice that was strange was that after my modem got the Blast profile downloaded to it, my connection worked and my new speed was confirmed but when I logged into the modem (192.168.100.1) I noticed that on the status page it said Offline for the modem status, on the signals page one of the upstream channels said T4 Timeout and my Logs had almost a dozen new errors that said Critical and warning next to them.

Can anyone tell me what that may be about? I've heard other posts on here of others with SB6121s getting lots of errors but I didn't start seeing them until I got upgraded to Blast.

That sounds similar to what pokesph See Profile experienced in this thread: »Re: [Connectivity] New SB6120/6121 Firmware Released

Try rebooting your modem. If that doesn't fix it, then try resetting the unit to factory defaults, followed by a reboot, as also suggested in that thread by koitsu See Profile.

MisterP

join:2012-10-11
US

I rebooted about a half hour ago (thought of it as I was typing up my last reply) and now the Status is operational, Signals all look within range and channel that was T4'ed says Success now, but I have gotten two T3 Timeouts already since rebooting and also a MIMO event whatever that is. Is this normal or is there still an issue?

Also, If I do a complete factory reset, will Comcast have to reprovision my modem? It was a PITA because they didn't know I had Blast and the corporate office is closed for tonight so I can't get them to send me a hit.



NetFixer
Snarl For The Camera Please
Premium
join:2004-06-24
The Boro
Reviews:
·Cingular Wireless
·Comcast Business..
·Vonage
·Comcast

said by MisterP:

I rebooted about a half hour ago (thought of it as I was typing up my last reply) and now the Status is operational, Signals all look within range and channel that was T4'ed says Success now, but I have gotten two T3 Timeouts already since rebooting and also a MIMO event whatever that is. Is this normal or is there still an issue?

Also, If I do a complete factory reset, will Comcast have to reprovision my modem? It was a PITA because they didn't know I had Blast and the corporate office is closed for tonight so I can't get them to send me a hit.

A few T3 and MIMO log entries after a reboot are not necessarily indicative of a problem. A factory default reset will not do anything that requires intervention from a Comcast tech.

I just did a factory default reset of my SB6121 and the screen shot images below were taken 17 minutes after doing it. Unless the error counts and the log entries are increasing at an alarming rate, you probably don't have a problem with your modem or your connection. Do what I just did, and then look at your logs and stats every hour to see if there is any evidence that the errors and log entries are steadily climbing by large numbers.









--
We can never have enough of nature.
We need to witness our own limits transgressed, and some life pasturing freely where we never wander.


telcodad

join:2011-09-16
Lincroft, NJ
kudos:5
reply to MisterP

said by MisterP:

Also, If I do a complete factory reset, will Comcast have to reprovision my modem? It was a PITA because they didn't know I had Blast and the corporate office is closed for tonight so I can't get them to send me a hit.

If your account has now been properly set, resetting the unit to factory defaults should not do anything that requires manual intervention from Comcast, as NetFixer See Profile said.

I was once worried about doing that myself, see: »Re: New speed for some areas- not so new for some others

MisterP

join:2012-10-11
US
reply to NetFixer

Thanks for the info NetFixer and telcodad; nice to have something to compare my stats to.

I clicked factory reset on the page and the screen just flashed; i never lost my connection but the logs are cleared and some other counters reset so I guess that's it lol.

I guess we haven't been bit by that firmware bug thats been going around for the sb6121s eh netfixer? Not sure why, maybe Comcast in our neck of the woods found the problem. I was worried when I started seeing that offline and T4 stuff that I for sure was messed up.